The Science of Conjecture: Evidence and Probability Before Pascal

by James Franklin

Astronomy has many difficulties with errors in measurement but very few with variability in the subject matter itself. The more mundane sciences may be able to measure more directly and accurately, but the variability in what is being studied makes the extraction of laws and the prediction of new cases very hard. Superficially, it is easy to know whether an herb cures a certain disease, by testing it on many cases and seeing if a cure results. Just occasionally, it is as easy as that, but almost always there are so many variables, spontaneous cures, extenuating circumstances, and possible excuses that it is almost impossible to extract a truth from any reasonable amount of data. It was only from the late nineteenth century that the sophisticated statistical techniques of biometry (modern statistics) were developed in agriculture and genetics and were applied in psychology, sociology, and drug trials.